Free temporary email API (disposable inboxes)

A free temporary email API for disposable inboxes you create and read over HTTP — test signups, read OTPs, and give agents throwaway addresses.

A temporary email API gives your code throwaway inboxes it creates and reads over HTTP — the programmatic version of a disposable-email site. It’s the right tool for testing signups, reading OTPs in CI, and handing an AI agent a one-off address.

Create a disposable inbox

curl -X POST https://login.ollastack.com/api/mailboxes \
  -H "Authorization: Bearer $TOKEN" -H "Content-Type: application/json" \
  -d '{"name":"throwaway","mode":"test"}'
# → { "id":"mbx_x", "address":"a1b2c3@test.ollastack.com" }

Use that address wherever you need a throwaway email. It’s a real, receiving address — not a black hole.

Read its mail

# block until the next message arrives
curl "https://login.ollastack.com/api/mailboxes/mbx_x/wait?timeout=60" \
  -H "Authorization: Bearer $TOKEN"
# → { "from":"...", "subject":"...", "codes":["920184"], "links":["..."] }

Codes and links come extracted, so you read codes[0] instead of parsing HTML.

Never spam-filtered (on purpose)

A test inbox is unfiltered — it sees every message it was sent, even spam-shaped ones. That’s exactly what you want for testing: a strict transactional email never disappears from under your assertion. (Persistent agent inboxes are filtered — different job.)

Temporary vs persistent

• Temporary (test) — throwaway, unfiltered, for CI and one-offs.
• Persistent (agent) — a chosen handle that lasts and is spam-filtered, for an identity. See agent email identity.

Bulk-clear an inbox and set a retention window so test mail purges itself.

Isolate parallel test runs

When several tests run at once, each needs its own mail so they don’t read each other’s. Two ways:

• One inbox per test — create a fresh disposable mailbox at the start of each test and tear it down after. Cleanest isolation.
• Sub-addressing one inbox — append a +tag to a shared address (a1b2c3+test42@test.ollastack.com) and filter received mail by the tag. Fewer inboxes, still isolated.

Either way, bulk-clear an inbox between runs and set a retention window so old test mail purges itself instead of piling up.

When NOT to use a temporary inbox

A disposable inbox is the wrong tool for a persistent identity — anything a real person will reply to over time, or an address that must survive across sessions. For that, use a persistent agent inbox (spam-filtered, a chosen handle). Temporary inboxes are for throwaway, single-use, and CI flows.

Where it fits

Disposable inboxes power OTP testing, CI email testing, and agent verifications. They’re part of the same email API — free, no credit card.

Create a temporary inbox — disposable, readable over HTTP, free.

Last updated June 21, 2026. Spotted something out of date? Email hello@ollastack.com.